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D - 4 CodeForces - 472... 阅读全文
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A - 1 CodeForces - 510AFox Ciel starts to learn programming. The first task is drawing a fox! However, that turns out to be too h... 阅读全文
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b站官方录播链接mikuB站官方账号：初音未来_Cryptonmiku saikoby KEI画师 阅读全文
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错排问题 错排问题是组合数学发展史上的一个重要问题，错排数也是一项重要的数。令 的一个错排，如果每个元素都不在其对应下标的位置上，即 ，那么这种排列称为错位排列，或错排、重排（Derangement）。我们从分析1 2 3 4的错排开始：1 2 3 4的错排有:4... 阅读全文
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C - A/B HDU - 1576要求(A/B)%9973，但由于A很大，我们只给出n(n=A%9973)(我们给定的A必能被B整除，且gcd(B,9973) = 1)。//题目这的gcd是 欧几里得算法Input数据的第一行是一个T，表示有T组数据。每组... 阅读全文
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C - 3 CodeForces - 580A Kefa decided to make some money doing business on the Internet for exactly n days. He knows that on the i-th day (1 ≤ i ≤ n) h 阅读全文
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C - 3 CodeForces - 580... 阅读全文
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B - 2 CodeForces - 69AA guy named Vasya attends the final grade of a high school. One day Vasya decided to watch a match of his f... 阅读全文
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C - 3 CodeForces - 271AIt seems like the year of 2013 came only yesterday. Do you know a curious fact? The year of 2013 is the fi... 阅读全文
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D - 4 CodeForces - 337AThe end of the school year is near and Ms. Manana, the teacher, will soon have to say goodbye to a yet ano... 阅读全文